A backlight module is a key element of liquid crystal display (LCD) panels. Since the liquid crystal in an LCD panel is not luminous, a backlight module is required to serve as a light source for the LCD panel.
Referring to FIG. 1, a backlight module includes a back plate 11, a circuit board 12, a plurality of light-emitting diodes 13, a reflector 14, a light guide plate 15, at least one diffuser plate 16 and at least one brightness enhancement film 17.
The light-emitting diodes 13 are disposed on and electrically connected to the circuit board 12. The circuit board 12 is connected to the back plate 11 by screws. The reflector 14 covers a part of the circuit board 12 that is exposed from the light-emitting diodes 13. In other words, the reflector 14 is formed with a plurality of through holes 141, each of which corresponds in position to a respective one of the light-emitting diodes 13.
During assembly of the backlight module, it is essential to precisely align the reflector 14 with the circuit board 12 so as to respectively receive the light-emitting diodes 13 in the through holes 141. The alignment procedure is time consuming and associated with increased manufacturing costs. In the event that the reflector 14 is misaligned with the circuit board 12, the reflector 14 may become deformed or damaged, resulting in lower production yields.
Moreover, the multi-layered structure of the back plate 11, the circuit board 12, and the reflector 14 makes the backlight module relatively bulky, and fails to meet market trends that favor thin and lightweight designs. Furthermore, during operation of the backlight module, the light-emitting diodes 13 generate massive amounts of heat. If the heat is not properly dissipated, lighting efficiency and the lifetime of the light-emitting diodes 13 may be adversely affected.
Accordingly, it is desirable to provide a backlight module with reduced thickness, improved heat dissipation, simplified manufacturing processes and reduced manufacturing costs so as to cater to the market trend.